DISCUSSION
This retrospective cross-sectional study found that patients diagnosed
with CLE, who underwent surgical lobectomy, were symptomatic compared
with the patients with conservative follow-up and those among the former
who were diagnosed in the neonatal and early infancy period. The most
common symptoms of the patients who underwent lobectomy at presentation
were respiratory distress, tachypnea, and retraction. The most common
symptom of the patients who were conservatively followed up was
coughing. As with studies in the literature, our study observed that the
most commonly involved lobes are the left upper and right middle lobes
(5-8,11). The CLE is currently defined as a rare congenital airway
malformation characterized by lobar hyperinflation that causes
respiratory distress in the neonatal and infancy period. Obstruction in
bronchial structures, increased aeration, compression atelectasis in
adjacent tissues, and mediastinal shift are observed in symptomatic
patients who are diagnosed within the first 6 months, mostly during the
first postnatal days (24). Early diagnosis (fetal ultrasound, etc.) is
important because tension pneumothorax can occur in these patients when
respiratory distress develops with the first postnatal inspiration and
when positive pressure ventilation is applied (25).
In our study, only two patients were diagnosed with fetal
ultrasonography, whose widespread use has resulted in more frequent
diagnoses of congenital pulmonary malformations (CPM). A multicenter
retrospective study in 2019 examined data from 506 patients with CPM and
observed CLE in 53 patients (10.3%) (26). The diagnosis of CPM without
CLE has been shown to be significantly more frequent with fetal
ultrasonography than with CLE, a result that has been attributed to the
nonspecific echogenicity and rarer occurrence of CLE in fetal
ultrasonography (26-28). Asymptomatic CLE with no mediastinal shift or
atelectasis is diagnosed late. When diagnosed, this condition is mostly
conservatively treated (29-30). CLE can go unnoticed in follow-up
ultrasounds and, as it progresses, can sometimes lead to severe
respiratory distress at birth (30). The presence of mediastinal shift
and atelectasis in AR at birth has been correlated to respiratory
distress and the need for neonatal intensive care during the neonatal
period. Ten percent of patients with CLE and severe symptoms undergo
surgical lobectomy during the neonatal period, mostly in the first week
postpartum (27,28). Given that our study was retrospective, detailed
fetal ultrasounds were not available for all of the conservatively
followed up patients; however, the patients with an incidental diagnosis
who were attended by a perinatologist were followed up.
In our study, CLE occurred within a wide age range, from the neonatal
period to 17 years of age. In recent years, CLE has been shown to have a
wide range of possible symptoms, from minimal pulmonary symptoms to
respiratory failure in the neonatal period (6,13,26). These differences
can vary depending on the lobar and segmental location of the CLE
(26,31). There are reports in the literature of patients diagnosed with
incidental segmental CLE at the age of 15 days who had a chest tube
inserted with the pre-diagnosis of pneumothorax during the neonatal
period and were subsequently diagnosed with CLE (8,32).
In our study, two patients with CLE were diagnosed incidentally in the
imaging performed for other reasons, and four patients were diagnosed in
the imaging performed for suspected foreign body aspiration and in the
FB imaging. A study reported on a patient who was examined with a
pre-diagnosis of CLE at the age of 48 days and was found to have foreign
body aspiration; there was also a case report of a patient with
suspected foreign body aspiration, who was diagnosed with CLE at the age
of 15 years (15,33).
In our study, left upper lobe involvement was more common in the
surgical group than in the conservatively treated group; however, the
difference was not statistically significant. CLE with left upper lobe
involvement is more symptomatic and more frequently requires surgery.
There are publications showing that patients with right middle lobe CLE
are generally asymptomatic and are conservatively treated; however, this
might be due to the higher frequency of left upper lobe CLE (34-36).
In line with studies in the literature, the pulmonary symptoms and
CLE-related imaging findings in our study regressed during the
conservative follow-up. Many studies have shown no lung infection or
malignant transformation during conservative follow-up (13,34-36). In
the patients who underwent surgery, alveolar emphysema was the most
common finding in the pathology specimens, with half of the specimens
presenting cartilage hypoplasia. In the literature, emphysematous
changes are the most common pathology findings, and accompanying
cartilage hypoplasia has less frequently been reported (36).
In our study, the rate of CHD and other accompanying diseases was 15%,
which is consistent with studies showing that the incidence of CHD
varies between 6% and 24% in patients with CLE (14,37,38).
The limitations of our study were: 1) the results of the fetal
ultrasounds could not be obtained for all patients due to the study’s
retrospective design; 2) the patients were followed up with other
diagnoses because our hospital is a reference center; and 3) the delay
before the diagnosis was relatively prolonged, especially in the
patients who underwent surgery. Due to technical issues (e.g.,
performing spirometry in patients too young to cooperate), detailed
pulmonary function tests such as impulse oscillometry could not be
performed on all patients.
In conclusion, we observed that respiratory distress and mediastinal
shift were more prominent in patients who underwent surgery with a
diagnosis of CLE compared with patients who were conservatively followed
up. We also observed that those who underwent surgery were diagnosed at
an earlier age. Clinicians should consider performing a detailed
anamnesis for patients with unresolved respiratory symptoms and
unilateral or bilateral increased ventilation. Clinicians should also
perform appropriate imaging tests and examinations (including FB) and
should consider CLE in the diagnosis.